Inhibitory Effect of A grimonia Pilosa Leaf Extract on the UV-Induced Photoaging-Related Ion Channel, ORAI1, and the Enzymes Tyrosinase and Elastase.

A grimonia pilosa Ledeb. has received considerable attention as a natural product for its applications in cosmetics owing to its anti-skin wrinkling and whitening effects. The ORAI1 ion channel is known to be involved in UV-induced photoaging. Additionally, tyrosinase and elastase are key enzymes in the process of wrinkle formation and pigmentation. We determined that A . pilosa leaf extract and its fractions (dichloromethane, ethyl acetate and n-butanol) inhibit this channel and associated key enzymes. Whole-cell patch-clamp experiments demonstrated that the ethyl acetate fraction had a potent inhibitory effect on I_ORAI1 (99 ± 1%) at 100 μg/mL. Ethyl acetate and dichloromethane fractions had tyrosinase inhibitory activity (46.1 ± 0.84% and 35.7 ± 1.40% at 330 μg/mL, respectively). Additionally, these fractions inhibited elastase activity by 48.3 ± 1.20% and 45.4 ± 1.51% at 330 μg/mL, respectively. Our results suggest that A . pilosa leaves are a potential anti-wrinkle and whitening agent. Practical Applications A grimonia pilosa has been widely used for the treatment of sore throat, headache, bloody dysentery, parasitic infection and eczema in traditional oriental medicine. Recently, it has also been used as an external application for the treatment of various dermatological problems, such as healing wounds, diminishing wrinkles, pigmentation and atopic dermatitis. However, to date, no report has detailed the mechanisms of A . pilosa's anti-photoaging activity. This research revealed that the extract of A . pilosa leaves meditates ORAI1 channel activity and directly inhibits tyrosinase and elastase activity. Therefore, A . pilosa may be a potential therapeutic agent in the prevention of UV-induced photoaging. [ABSTRACT FROM AUTHOR]